ETFs with the Biggest Fund Flows

More From ETF Strategist - Fixed Income

Biggest Net Flows Year-To-Date

Exchange Traded Funds (ETFs) offer investors instant diversification at low cost — tracking indexes, commodities, currencies or a basket of managed assets — with the ability to trade like stocks. Investors have been increasing their positions in these instruments, with assets in U.S.-listed ETFs and ETNs (Exchange-Traded Notes) totaling $1.2 trillion as of April 2012, a 6 percent increase compared to April 2011, according to the ETF Industry Association. According to the association, ETF net cash inflows totaled approximately $3 billion in April, with year-to-date positive net cash flows totaling $58.9 billion.

ETF inflows and outflows show where investors are putting their money. They signal bullish or bearish attitudes from investors toward the underlying strategy of an ETF, as the market places bets and pushes capital in the direction of a specific fund. These cash flows change the value of the assets under management and act as proxies for what investors are looking for in the market. For instance, a recent report noted that metals ETFs were attracting those looking for safe haven investments away from U.S. Treasurys, signaling a preference for hard assets.

As the lower cost alternative to mutual funds, ETFs continue to attract more of investors' money. Although ETF assets are still dwarfed by the nearly $8 trillion mutual fund industry, ETFs raked in double the amount of new money that mutual funds did last year: $119 billion for ETFs, compared to $59 billion for mutual funds.

The following is a list of ETFs that have seen the largest absolute net inflows and outflows year-to-date through the market close on May 29, according to data from IndexUniverse.com, an independent source for information on ETFs, indexes, and index funds. Assets under management (AUM) and top holdings are according to data from Morningstar based upon the most recent portfolio date. Market information on the listed ETFs is provided by the CNBC Analytics team.

So, which ETFs are attracting or shedding the most capital? Click ahead for the ETFs with the biggest net cash flows year to date.